leading Republican politician after the American Civil War who abandoned his party to serve as U.S. secretary of state (1893–95) under the Democratic administration of President Grover Cleveland.

After serving as a brevet major general in the Union Army during the Civil War, Gresham, a lawyer, was active in Indiana Republican affairs. He served as a U.S. district judge in Indiana during 1869–83. Chester A. Arthur (Arthur, Chester A.), who was considering Gresham as a possible running mate, appointed him as postmaster general (1883–84).

By the time of the Republican convention of 1884 Gresham had become a prominent and respected Republican; he was considered by the party as a presidential candidate but lost to James G. Blaine. In 1888 Gresham was again a leading candidate for the Republican presidential nomination; he ran second to John Sherman of Ohio on the first ballot but ultimately lost the nomination to Benjamin Harrison. Along with other disaffected Republicans, Gresham in 1892 endorsed Grover Cleveland (Cleveland, Grover), the Democratic candidate for president. Gresham was especially drawn to Cleveland because of the latter's pledge to reduce the tariff.

Appointed secretary of state by Cleveland in 1893, he urged the president to withdraw from Senate consideration the controversial treaty annexing Hawaii, which had been negotiated by the Harrison administration. Earlier, Gresham had denounced the United States' complicity in the Hawaiian revolution as imperialistic. Although he brought about diplomatic solutions to many international disputes, Gresham is not remembered for any major contributions to U.S. foreign policy.